Below is a technical breakdown of what this file likely is and how to handle it. Likely Origin: Security Surveillance
A file named "g9640.mp4" is likely a proprietary surveillance clip that has been converted or exported to a standard format for viewing on standard Windows or mobile media players.
The "9640" part is typically a sequential ID assigned by the camera or the system during recording or export. Technical Properties of MP4
Even after conversion, the file may still contain EXIF data or internal atoms (like moof atoms) that provide forensic details about the camera model or recording time. Security Assessment
You can typically open this file using VLC Media Player or standard OS video apps.